"Phantom" sound with speakers and devices muted/unplugged??

Hello :confused

I posted this in Drivers forum but now realize after updating all my drivers etc; it is more of a Hardware issue. Sorry.

I have an extremely bizarre problem.

I recently bought an eMachine with onboard RealTek HD sound...

I'm running Vista Home Premium.

Even with speakers unplugged, and audio devices muted/disabled;
My computer insists on making low bass type noises when I game.

Even with the game sound options off, and the built in monitor speakers' audio feed cables never plugged in.

Is it possible that I am getting some kind of feedback? I do have a Klipsch 5.1 woofer under my computer desk, but I even pulled its power cord.

These noises are so annoying and bass oriented, I can't use my computer late at night (I live in an apartment with sound curfews), and there are no speakers/output devices plugged into ANY jack at all!

Is it possible to get feedback like this perhaps from my monitor's built in speakers? This problem is driving me berserk!

Basic Specs :
3.17ghz AMD Athlon X24050e
nVIDIA GF 6150SE onboard GPU
3GB DDR2 RAM
Hannspree LCD 22" monitor w/ built in speakers..
-also; a dormant Klipsch 5.1 4 speaker satellite system w/ subwoofer that has NOT been hooked up in any way-

Thanks in advance for any ideas or theories.
>_@
-Seif

 

Could it be the computer vibrating against something?

Is there a built in speaker?

 

"My computer insists on making low bass type noises when I game."

Is there a fan speed controller in it, do the fans speed up when under load as you may have a fan with a bent spindle or malformed blade.

 

Thanks guys for the ideas.. however..
A) My computer has a built in speaker, but only the regular primitive one that can just beep on an error if my sound is turned off.. this is bass.

B) I thought it was my fan as well, for a long time.. however, the bassy noises aren't just random/continuous humming; they are the sounds of the game I am playing (i.e. FPS gunshots and such, perfectly synced with the game.)

I am wondering if even an unplugged woofer (power cord detached) sitting right under my desk where the tower sits... could possibly be getting some sort of interference/feedback/electrical impulses from some part of the whole system, and hence making weak pickups of these. But with no power whatsoever to the woofer, I find this incredibly unlikely.

One question your comments have raised, however.
My PSU/CPU fan -does- kick in loudly when running almost any app/performing any task. And the bass noises are indeed reverberating through the tower case, I can feel the humming towards the back of it (suspecting PSU fan)... Can someone perhaps reccomend a good fan speed/temp free or trialware program, so I can measure if the fan is indeed changing RPMs so oddly? Also.. for my system specs, what would be a normal range for the system/cpu fans if I'm running something that demands say up to 2/3 of my resources?

Sorry for all the questions, but I think the fan theory might be close.

Thank you so much for your time to answer this bizzare question

Thanks for your time,
Seifer J. Arris

 

Sorry, forgot to answer this one.. yes, there is a controller if you mean software wise (BIOS/Windows Device Manager settings for fan use..). And yes as I said in my reply, they do indeed sound to be speeding up under any load whatsoever, even starting Windows, or launching a browser. Thanks!